Steam trap



J. THOMSON July 17, 1951 STEAM TRAP Filled Oct. 6, 1947 I l I b AMA A Patented July 17, 1951 STEAM TRAP John Thomson, Edinburgh, Scotland Application October 6, 1947, Serial No. 778,226 In Great Britain June 17, 1947 The'invention relates to apparatus for the removal or ejection of the water ofcondensation from steam or air pipes, vessels, receivers, jackets, separators, and steam heating systems, subjected to either high or low pressure steam or air for the generation and transmission of power or for process work and commonly known or designated under the general title of steam traps.

The invention ha for its object the elimination of ancillary valves which co-operate with fixed or movable valve seatings. Such valves and valve seatings are subject to rapid wear and tear due to the abrading action of water and steam at high velocity and require frequent attention and renewal if loss of heat or air due to excessive leakage is to be avoided.

The invention is applicable to the water-borne upright open bucket type of steam trap in which the openin or closing of the outlet to discharge the water or other fluid is eifected by the relative movement of a movable ported tube concentrically disposed internally within a fixed outer tube contained within a closed vessel having inlet and outlet openings, the vessel being pressure-tight under steam, water or air pressure, and the invention consists in forming the termination of the ported tube at its upper end as an unimpeded outlet of nozzle formation.

According to the present invention the movable ported tube is attached to the open bucket and terminates at its upper or discharge end in an outlet of a geometrically formed tapered or nozzle formation so that the extreme internal diameter of the outlet opening is relatively smaller than the internal diameter of the movable tube and the discharge of fluid is unimpeded. The

discharge end of the movable tube is so formed.

with the object of providing, when the trap is in operation, a powerful and positive downward thrust to the bucket, thereby enabling the fluid content of the bucket to be rapidly discharged. In consequence, owing to the rapid gain of buoyancy by the bucket, a powerful upward reacting thrust is imparted to the bucket and inner tube, which ensures rapid closure to discharge. This rapid unimpeded action and reaction is important in that the liability of the movable member to attain a state of equilibrium before the discharge is completely closed, which would result in a constant leak or dribble being maintained, is avoided.

The invention will be more readily understood by reference to the accompanying drawings in which Figs. 1 and 2 are sectional views representing an example of an upright bucket type of steam trap incorporating my invention.

Fig. 1 is an example of an open upright bucket type of float 2 contained within a water chamber 1. To the bottom of the float or bucket 2 is rigidly attached a brass or gunmetal or other metal 2 Claims. (Cl. 137103) tube 4. This tube 4 slides easily and smoothly without perceptible slackness within an outer brass or gunmetal or other metal tube 3 which is rigidly attached at its upper end to a discharge connection 8 on the body of the chamber l. The connection 8 constitutes an extension of a discharge or outlet channel 9 for the water content of the trap. The upper end of the inner tube 4 is tapered or otherwise reduced to give it a nozzle formation 6. At a predetermined position on the inner tube, two ports or openings 5 are made diametrieally opposite each other (see Fig. 2). These ports or openings 5 may be formed rectangular, circular or otherwise and are of sufficient area to give a free discharge.

The operation is as follows: The trap having been connected at its inlet ID to the vessel to be drained and at it outlet II to the discharge, it is desirable before putting the trap into operation that the water chamber 1 be primed or supplied with water to such a level that the bucket float 2 is waterborne and the ports or openings 5 in the inner tube 4 are sealed by the outer tube 3. Connection is then made with the vessel to be drained and steam and water of condensation admitted into the water chamber 1. The gradual accumulation of Water eventually raises the buoyant bucket float to a limiting position (shown in Fig. 1 by the dotted outline of the bucket float and inner tube 4). The accumulation of water in the water chamber 1 continues until the water overflows into the bucket float 2. This addition of weight to the bucket boat 2 lessens its buoyancy and it begin to sink until the ports or openings 5 in the inner tube 4 attached to the bucket float 2 become uncovered. A discharge of water immediately occurs. Owing to the nozzle formation 6 of the open discharge end of the inner tube 4, a downward impulse or thrust is imparted to the bucket float 2, thereby enabling greater freedom for the discharge of the water content of the bucket float 2. consequent on the rapid emptying of the bucket float 2 a positive upward impulse or thrust due to the increase in buoyancy of the bucket float 2 is exerted. This becoming insistent, the bucket float 2 moves upward sharply, closing the ports or openings 5, and further discharge ceases. So long as the trap remains in direct connection with the vessel being drained the operation is automatically repeated. A port l2 may be provided to connect the inlet passage III with the upper part of the chamber 1 to equalise the pressure of steam or air above and below the water content of the steam trap and so avoid eruptive ebullition of the water content or water hammer when steam or air under pressure is admitted to the chamber 1.

I claim:

1. A steam trap comprising a chamber having an inlet passage discharging into the lower por-- lower end of said outer tube by rising and falling movement of the float, the upper end of the ported tube being open, unimpededandLgeomtrically formed to an upwardly tapered 'no'z'zle formation.

2. A steam trap comprising a chamber having an mletaport at itsr-lower end, =adischarge. passage eopening centrally from the upper end-10f said "chamber, .a ;centrally disposed pendant .tube attached at-its upper end tosaid' dischargegpassage, a bucket v floatdisposed within 1 said chamher, an inner tube centrally secured within said float-rand having a-port in its wall uncovered by theilower end ofsaid pendant tube -whensaid float is not "waterborne and covered by the lower end .of said pendant tube when said'float rises above -apredetermined level and in which the inner-tube ha anunimpeded open upper end-dis- 4 charging into said discharge passage and geometrically formed in tapered formation at its upper end, and the discharge passage being conically. for-med to accommodate the-tapered formation ofthe upper end of the said inner-tube.

JOHN THOMSON.

REFERENCES CITED rThefollowing references are of record in the 'UNITED STATES PATENTS I Number Name Date 25,510 Jenkins Sept. 20, 1859 72,088 Saunders l Dec. 10, 1867 130390 TDick Au 13,1872

$22,733 10001:. T Mar. 4, 1890 4 512294= 'Stifel May'1'2, 1891 A 94'Z, 801 'Cocipe'r "Feb.'1,-191'0 1,156,684 Higgins Oct. 12,1915

-FOREIGN PATENTS Number Country 1 Date 13,621 'Gre'atBritai'n 0f"1890 l'7,800 Great Britain of1890 437,244 Germany "of"1'926 

